Fix backslash escaping for failed build cleanup filters

[dirgim]

Fix for failed build cleanups - the backslash wasn't escaped.

[lslebodn]

+1 it fixed issue for me:

TASK [os_temps : include_tasks] **************************************************************************
fatal: [localhost]: FAILED! => {"reason": "Syntax Error while loading YAML.\n  found unknown escape character\n\nThe error appears to have been in '/root/contra-env-setup/playbooks/roles/os_temps/tasks/setup_containers.yml': line 38, column 70, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n- name: \"Check for all failed apps on the cluster\"\n  shell: \"{{ oc_bin }} get all | egrep 'Failed|Error' | egrep 'builds\\/' | awk '{print $1}' | awk -F'/' '{print $2}' | sed 's/-[0-9+]//g' \"\n                                                                     ^ here\nWe could be wrong, but this one looks like it might be an issue with\nmissing quotes.  Always quote template expression brackets when they\nstart a value. For instance:\n\n    with_items:\n      - {{ foo }}\n\nShould be written as:\n\n    with_items:\n      - \"{{ foo }}\"\n"}
        to retry, use: --limit @/root/contra-env-setup/playbooks/setup.retry

PLAY RECAP ***********************************************************************************************
localhost                  : ok=22   changed=16   unreachable=0    failed=1